In that same window, click the File Sharing tab. (If you’ve plugged a USB hub into the Base Station and attached multiple hard drives to it, you’ll see all the devices plugged into that hub.) Click that and you should see the name of the disk connected to the Base Station. In the window that appears, you’ll see a Disks tab. Select the Base Station within the AirPort Utility window and click the Manual Setup button. Plug the drive into the AirPort Extreme Base Station’s USB port and launch AirPort Utility (which you’ll find in the Utilities folder within the Applications folder at the root level of your startup drive). First, be sure that the drive is formatted as a Mac OS Extended volume (you do this in Disk Utility).

What do I then do to be able to use it on my home network?

I connected my external drive to the Airport Extreme Base Station with a USB cable. Reader Art Hall would like to take advantage of the USB port on his AirPort Extreme Base Station.